archive.h

   1 /*
   2  * Copyright (c) 2001, Robert Collins.
   3  *
   4  *     This program is free software; you can redistribute it and/or modify
   5  *     it under the terms of the GNU General Public License as published by
   6  *     the Free Software Foundation; either version 2 of the License, or
   7  *     (at your option) any later version.
   8  *
   9  *     A copy of the GNU General Public License can be found at
  10  *     http://www.gnu.org/
  11  *
  12  * Written by Robert Collins  <rbtcollins@hotmail.com>
  13  *
  14  */
  15
  16 #ifndef _ARCHIVE_H_
  17 #define _ARCHIVE_H_
  18
  19 /* this is the parent class for all archive IO operations.
  20  * It
  21  */
  22
  23 /* The read/write the archive stream to get the archive data is flawed.
  24  * The problem is that you then need a *different* gzip etc class to be able
  25  * to ungzip a gzip from within an archive.
  26  * The correct way is to
  27  * 1) retrieve the file name.
  28  * 2) the user creates their own output object.
  29  * 3) the user calls extract_file (output strea,).
  30  */
  31
  32 typedef enum
  33 {
  34   ARCHIVE_FILE_INVALID,
  35   ARCHIVE_FILE_REGULAR,
  36   ARCHIVE_FILE_HARDLINK,
  37   ARCHIVE_FILE_SYMLINK,
  38   ARCHIVE_FILE_DIRECTORY
  39 }
  40 archive_file_t;
  41
  42
  43 class archive:public io_stream
  44 {
  45 public:
  46   /* get an archive child class from an io_stream */
  47   static archive *extract (io_stream *);
  48   /* get an ouput stream for the next files from the archive.
  49    * returns NULL on failure.
  50    * The stream is not taken over - it will not be automatically deleted
  51    */
  52   virtual io_stream *extract_file () = NULL;
  53   /* extract the next file to the given prefixURL+Path in one step, and name it with the
  54    * given suffix.
  55    * returns 1 on failure.
  56    */
  57   static int extract_file (archive *, const char *, const char *, const char * = NULL);
  58
  59   /*
  60    * To create a stream that will be compressed, you should open the url, and then get a new stream
  61    * from compress::compress.
  62    */
  63   /* read data - not valid for archives (duh!)
  64    * Could be made valid via the read-child-directly model
  65    */
  66 //  virtual ssize_t read(void *buffer, size_t len) {return -1;};
  67   /* provide data to (double duh!) */
  68 //  virtual ssize_t write(void *buffer, size_t len) { return -1;};
  69   /* read data without removing it from the class's internal buffer */
  70 //  virtual ssize_t peek(void *buffer, size_t len);
  71 //  virtual long tell ();
  72   /* try guessing this one */
  73 //  virtual int error ();
  74   /* Find out the next stream name -
  75    * ie for foo.tar.gz, at offset 0, next_file_name = foo.tar
  76    * for foobar that is an compress, next_file_name is the next
  77    * extractable filename.
  78    * The way this works is that when read returns 0, you are at the end of *a* file.
  79    * next_file_name will allow read to be called again, if it returns !NULL
  80    */
  81   virtual const char *next_file_name () = NULL;
  82   virtual archive_file_t next_file_type () = ARCHIVE_FILE_INVALID;
  83   virtual const char *linktarget () = NULL;
  84   virtual int skip_file () = 0;
  85   /* if you are still needing these hints... give up now! */
  86 //  virtual ~compress ();
  87 protected:
  88   void operator= (const archive &);
  89   archive () {};
  90   archive (const archive &);
  91 private:
  92 //  archive () {};
  93 };
  94
  95 #endif /* _ARCHIVE_H_ */